1 Degree project, 30 ECTS January 25 2019
Version 2
Author: Linnea Sundman, Bachelor of Medicine School of Medical Sciences Örebro University Sweden Supervisor: Ann-Kristin Rönnberg, MD PhD Department of Obstetrics and Gynecology Örebro University Hospital Sweden Word count
Abstract: 232 Manuscript: 2861
The impact of obesity on outcome of delivery
2 ABSTRACT
Introduction: Pre-pregnancy obesity was prevalent among 18% of women who delivered in Örebro in 2017. The rate has increased and previous international studies have identified obesity as a major risk factor for poor reproductive health among women.
Aim: To analyze the association between maternal pre-pregnancy obesity and major obstetrical outcomes within the Örebro region.
Methods: This retrospective observational study collected data from 1st Jan. 2015 to 30th Jun. 2018 via the Swedish Pregnancy Register. All women, who delivered simplex deliveries in the Örebro region during the study period, were eligible for inclusion. Exclusion criteria were BMI <18.5 kg/m2, delivery by forceps, incomplete data and admission to antenatal care at >17 gestational weeks. Women were categorized into obese (BMI >30 kg/m2)or non-obese (BMI <29.9 kg/m2) and compared by several obstetrical outcomes.
Results: Of the 6846 included women, 17.8% were classified as obese. Obese women had several adverse maternal obstetrical outcomes. They had a significantly increased risk of undergoing induction of labor (OR 1.85), cesarean delivery (CD) (OR 1.46), emergency CD (OR 1.38), repeated CD (OR 1.47), having longer cesarean duration, higher total blood loss, and higher fetal birthweight.
Conclusions: Pre-pregnancy obesity, among women in the Örebro region, is associated with significantly increased risk of adverse maternal outcomes during delivery and intervention before, during and after delivery should be further studied in order to minimize risk of complications in this risk group.
3 ABBREVIATIONS
AGA-appropriate for gestational age BMI-body mass index
CD-cesarean delivery CI-confidence interval IQR-inter quartile range LGA-large for gestational age LMH-low molecular heparin OR-odds ratio
SD-standard deviation
SGA-small for gestational age SPR-Swedish Pregnancy Register VD-vaginal delivery
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Table of contents
1. Introduction ...5
2. Aim ...6
3. Material and methods ...7
3.1 Data collection and subjects ...7
3.2 Baseline characteristics ...7 3.3 Primary outcome ...7 3.4 Secondary outcome ...8 3.5 Statistics ...8 3.6 Ethical consideration ...8 4. Results ...9
4.1 Overview and baseline characteristics ...9
4.2 Primary outcomes... 10
4.3 Secondary outcomes ... 13
5. Discussion ... 15
6. Conclusion ... 18
5
1. Introduction
Maternal obesity has increased during the last decades and worldwide it is reaching epidemic proportions [1]. From 1980 to 2013 the frequency of obese and overweight individuals increased from 857 million to 2.1 billion [2]. During 2017, 15% of pregnant women in Sweden and 18% in Örebro were obese [3]. WHO defines obesity as body max index (BMI) above 30 and subclasses of obesity as, class I (BMI: 30-34.9 kg/m2), II (BMI: 35-39,9 kg/m2) and III (BMI: >40 kg/m2) [4]. Being obese puts both the mother and baby at risk [5]. Previous studies have shown that maternal obesity is linked to adverse pregnancy and delivery
outcomes such as decreased rate of breastfeeding [2], venous thrombosis during pregnancy [6], increased risk of stillbirth [7], preterm delivery [8], macrosomia, pregnancy-induced hypertension, preeclampsia, gestational diabetes [9–11], labour induction, failed induction, prolonged labour [7], failure to progress in cervical dilation [11,12], instrumental vaginal delivery (VD) [13] and maternal death [14].
Rates of cesarean deliveries (CD) are also increasing [16] and rates are higher among women with prepregnancy obesity [5,7,10–12], increasing with BMI severity [5,12,16]. Earlier studies show that increased BMI results in more complications during and after CD, for example prolonged operative time [6,12,17], which also increases with increasing severity of obesity [18]. Moreover, prolonged anaesthesia time, increased hospital admission and
operational costs, postpartum hemorrhage, difficulty to palpate landmarks [6], seroma formation [17] and postoperative wound infection are seen more frequently when operating on obese women [5,17–19]. Existing literature suggests postpartum haemorrhage doubles with obesity and that hemorrhage increases with obesity severity [20].
Due to the increasing base of evidence of adverse obstetrical outcomes among obese women, the Örebro region introduced new guidelines concerning maternal health care for obese women the spring of 2017. The guidelines are mainly based on evidence generated from international studies and knowledge of local obstetrical outcomes in the obese population is lacking. The new guidelines include an increased focus on morbidly obese women (BMI >40 kg/m2)who are recommended special planning of delivery with antenatal anesthesiologist consultation, assessment of the need for prophylactic medication in terms of thrombosis (low molecular weight heparin (LMH)), infection during CD (antibiotics) and aspiration injury during delivery (antacids). Furthermore, morbidly obese women having CD should have two
6 surgeons, preferably regional anaesthesia, subcutaneous suturing and receive LMH six weeks postpartum (appendix 1).
2. Aim
The primary aim was to analyse the association between maternal pre-pregnancy obesity and major obstetrical outcomes within the Örebro region.
The secondary aim was to audit the compliance among health care providers to the regional guidelines implemented in 2017.
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3. Material and methods
3.1 Data collection and subjects
The study was performed as a retrospective observational study. Data was collected from the national Swedish Pregnancy Register (SPR).
All women who delivered simplex pregnancies in the Örebro region between 1st January 2015 and 30th June 2018 were eligible for initial inclusion. Exclusion criteria were BMI <18.5 kg/m2, missing data, delivery by forceps and initial antenatal visit >17 weeks of gestation.
Women were categorized according to WHO standards as non-obese if BMI 18.5-29.9 kg/m2 and obese if BMI >30 kg/m2.
3.2 Baseline characteristics
Baseline characteristics collected were mean age, Scandinavian origin (y/n), level of education (no education or elementary school/high school/university), occupation
(employed/unemployed), parity, previous CD, median gestational length at registration, mean BMI and BMI categories (normal weight/overweight/obese grade I-III). Maternal BMI was calculated from self-reported height and weight measured in a standardized manner at admission to antenatal care.
3.3 Primary outcome
Primary aim was to compare major maternal obstetrical outcomes in relation to pre-pregnancy obesity. Outcome variables collected were: median gestational length at delivery (weeks), rate of premature delivery (<37+0 w) and induction of labour (%), mode of delivery (normal VD/instrumental VD/CD), rate of emergency CD (%) and rate of repeated CD among women with one previous CD (%), rate of CD in Robson* group 1 (%), mean duration of CD (min), mean total blood loss (ml), mean fetal birthweight (g) and birthweight in relation to
gestational age (SGA/AGA/LGA).
*The Ten Group Classification System (TGCS) is used in Sweden to classify women before delivery based on obstetric parameters (parity, gestational age, previous CD, onset of labour, fetal presentation and number of foetuses). Women in Robson 1 have single cephalic
pregnancies and are nulliparous, with spontaneous start of labour at >37 weeks gestation [21,22].
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3.4 Secondary outcome
The secondary aim of the study was to perform an audit of adherence to Örebro´s regional guidelines regarding maternal care given to morbidly obese women. Women included in the audit had a grade III obesity (BMI >40 kg/m2) and delivered between 1st November 2017 and 30th June 2018, thus receiving antenatal care after the implementation of new guidelines. Data was collected from medical records and outcome in terms of referral to specialized care, documented delivery plan, anaesthesiology consultation, rate of ultrasound examinations before delivery, antacids per os during delivery, prophylactic anticoagulation postpartum (y/n and duration), adequacy in prophylactic anticoagulation ordination intrapartum, rate of regional anaesthesia during CD, prophylactic antibiotics during CD, subcutaneous closure (y/n) and number of surgeons at CD (>1). Compliance was considered high (>90%), intermediate (>70%) and low (<70%).
Baseline demographics were also reviewed in the audit in terms of mean age, parity, BMI (mean, minimum, maximum), rate of CD and emergency CD, duration of CD (mean, minimum, maximum) and mean patient-reported experience of delivery (VAS).
3.5 Statistics
Statistical analyses were performed in IBM SPSS Statistics, version 22. Distribution of variables was examined using histogram and box-plot. Normally distributed variables were reported by mean values with standard deviation and skewed variables by median and interquartile range or logarithmic mean and quartiles. Pearson Chi-square test and independent samples t-test with 95% confidence intervals (CIs) were used to compare differences between the groups. Two-sided significance tests were used and a p-value of <0.05 was regarded as statistically significant. Comparison of >2 categorical variables were made by Chi-square test for trend. Risk estimates were calculated by binary logistic
regression. Adjustment for potential confounding factors was performed in relative risk analysis.
3.6 Ethical consideration
Documents containing civil right number were only accessible through a code key deposited by the authors. All data were anonymous and presented on a group level. The study, which is a quality management, was approved by the director of Gynaecology department in Örebro University Hospital.
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4. Results
4.1 Overview and baseline characteristics
During the study period, 8018 women delivered in the Örebro Region. A total of 6846 women met the inclusion criteria, had complete data and were included in the analysis (fig 1). The distribution of pre-pregnancy BMI for the women classified 5630 as non-obese (BMI <29.9 kg/m2) and 1216 as obese (BMI >30kg/m2). There were 16.0% of the obese and 11.7% of the non-obese group excluded.
The mean age and median gestational length at registration did not differ in the two groups (table 1). Women with pre-pregnancy obesity had statistical significant lower rates of Scandinavian origin, lower level of education and higher rates of unemployed. The obese group had an increased rate of previous CD and a lower rate of primiparous women.
Figure 1. Flowchart of women in the study. Registered simplex deliveries in the region Örebro during study period 1st Jan. 2015 to 30th Jun. 2018 n=8018 Exclusions BMI <18.5 kg/m2 n=189 Delivery by forceps n=2 Missing data n=763 >17 gestational weeks at admission to antenatal care n=456
n= 1172
Group of obese women, BMI >30 kg/m2
n=1216 Eligible women with complete data included for analyses
n=6846
Group of non-obese women, BMI <29.9 kg/m2
10 Table 1. Baseline demographics of study population (N=6846).
Outcome Non-obese
n=5630
Obese n=1216
p-value
Age, mean yrs (SD) 30.5 (4.9) 30.4 (5.1) 0.734
GL at admission, median week (IQR) 7.0 (3) 7.0 (3) 0.984
Previous CD % (n) 8.6 (485) 12.3 (150) <0.001
Null parity % (n) 42.0 (2362) 35.5 (432) <0.001
Scandinavian origin % (n) 76.4 (4304) 71.3 (867) <0.001 Education % (n)
Elementary school/no education High school University 10.2 (573) 40.1 (2260) 49.7 (2797) 18.1 (220) 51.6 (627) 30.3 (369) <0.001c Occupation % (n) Employeda Unemployedb 90.4 (5087) 9.6 (543) 84.8 (1031) 15.2 (185) <0.001
Pre-pregnancy BMI (kg/m2), mean (SD) 23.8 (2.9) 34.4 (3.8) NA BMI (kg/m2) category % (n) Normal weight (18.5-24.9) Overweight (25.0-29.9) Obese grade I (30.0-34.9) grade II (35.0-39.9) grade III (>40.0) 66.2 (3729) 33.8 (1901) 64.1 (780) 26.3 (320) 9.5 (116)
SD=standard deviation, IQR=inter quartile range, BMI=body mass index, GL= gestational length, CD=cesarean delivery, NA=not available
a student/employed/parental leave b unemployed/sick leave/others cChi-square test for trend
4.2 Primary outcomes
Women with pre-pregnancy obesity had a significantly increased risk of having induction of labor (OR 1.85, CI 1.60-2.13), CD (OR 1.46, CI 1.25-1.71), emergency CD (OR 1.38, CI 1.04-1.83) and repeated CD after one previous CD (OR 1.47, CI 1.03-2.09) (table 2). Obese women were less likely to have a normal VD (OR 0.78, p<0.001). The mean duration of CD was significantly longer (39 vs 45 min, p<0.001) in obese women. Total blood loss at VD was significantly higher in the obese group (p=0.012) but there was no significant difference in blood loss during CD (p=0.197). Fetal birthweight was higher in the obese group (p<0.001) and the risk for delivering a large for gestational age (LGA) infant was significantly increased (OR 2.42, CI 1.91-3.07). The prevalence of premature delivery was higher in obese than non-obese women, although not statically significant (p=0.295).
11 There was a significant difference in baseline variables such as parity and rate of previous cesarean between the groups, with a higher rate of nulliparous women among non-obese women and a higher rate of previous CD among obese women. Adjusting for these differences in logistic regression analysis did not significantly alter our risk estimates of adverse outcomes but resulted in a further elevated risk for CD among obese women independent of parity (OR 1.49) and decreased risk after adjustment for previous CD (OR 1.36). Obesity was also an independent risk factor for induction of labor after adjustment for parity (OR 1.88).
12 Table 2. Comparison of maternal and fetal delivery outcomes among non-obese (BMI
<30kg/m2) and obese women (BMI >30kg/m2) in Örebro (N=6846).
aadjusted for previous CD badjusted for parity c logarithmic analysis
IQR=inter quartile range, Q1=25th percentile, Q3=75th percentile, SD=Standard Deviation,
OR=Odds Ratio, CI=confidence interval, GL= gestational length, CD=cesarean delivery, VD= vaginal delivery, SGA=Small for Gestational Age (>2 SD below the mean birthweight), AGA=Appropriate for Gestational Age, LGA=Large for Gestational Age (>2 SD above the mean birthweight), NA=not available
Outcome Non-obese n=5630 Obese n=1216 p-value
OR (CI) adj. OR (CI) GL at delivery, median week (IQR) 39.0 (2) 39.0 (2) 0.630 NA
Premature delivery (<37+0 w) % ( n) 6.0 (335) 6.7 (82) 0.295 1.14 (0.89-1.47) 1.18 (0.92-1.52)b Induction of labor % (n) 17.4 (982) 28.0 (341) <0.001 1.85 (1.60-2.13) 1.88 (1.63-2.17)b Normal VD % (n) 78.0 (4389) 73.3 (891) <0.001 0.78 (0.67-0.89) 0.73 (0.63-0.84)b Instrumental VD% (n) 6.7 (376) 5.8 (70) 0.237 0.85 (0.66-1.11) 0.95 (0.73-1.25)b CD % (n) Emergency CD % (n) 15.4 (865) 52.5 (454) 21.0 (255) 60.4 (154) <0.001 <0.001 1.46 (1.25-1.71) 1.38 (1.04-1.83) 1.36 (1.15-1.61)a 1.49 (1.27-1.74)b Repeated CD % (n) 50.9 (247) 60.0 (90) 0.035 1.47 (1.03-2.09) NA CD in Robson 1 % (n) 7.1 (112) 10.2 (23) 0.095 1.49 (0.93-2.39) NA CD duration (min), mean (SD) 39 (12) 45 (14) <0.001
Total blood loss (ml), meanc (Q1-Q3) Total blood loss CD, meanc (Q1-Q3) Total blood loss VD, meanc (Q1-Q3)
481 (350-650) 584 (400-850) 464 (300-600) 502 (350-700) 554 (400-800) 489 (350-650) 0.012c 0.197c 0.006c Fetal birthweight (g), mean (SD) 3497 (562) 3576 (633) <0.001 Fetal birthweight in relation to
gestational age % (n) SGA AGA LGA 3.7 (210) 92.4 (5200) 3.9 (220) 4.3 (52) 86.8 (1055) 9.0 (109) 0.368 Ref. <0.001 1.15 (0.85-1.57) Ref. 2.42 (1.91-3.07) 1.23 (0.90-1.68)b 2.32 (1.82-2.95)b
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4.3 Secondary outcomes
The audit of adherence to new regional guidelines report a high compliance in referral to specialized maternal care, plan for delivery, anesthesiologist consultation, prophylactic anticoagulation intrapartum, prophylactic intravenous antibiotics during CD and additional surgeons (table 3). There was a low compliance to use of antacids during delivery,
14
BMI=body mass index, SD=standard deviation, CD=cesarean delivery, US=ultrasound, NA=not available
aAppendix 1
Table 3. Audit of compliance to new regional guidelines for maternal care of morbidly obese women (BMI >40 kg/m2) in Örebro during 1st Nov. 2017 to 30th Jun. 2018. (N=34)
Age, mean yrs (SD) 30.2 (4.7)
Null parity % (n) 50 (17)
BMI kg/m2,mean (SD) Range (min-max)
Rate of cesarean delivery (CD) Rate of emergency CD Duration of CD (min), mean (SD) Range (min-max)
Patient reported experience of delivery, mean VAS 43.1 (3.1) 40-53 41.2 (14) 78.6 (11) 44 (10) 26-56 7.81
Audit outcome Rate %
(n)
Grade of compliance
Comment Referral to specialist care 100 (34) High
Documented plan for delivery 91.2 (31) High Anesthesiologist consulted prior to
delivery
94.1 (32) High Ultrasound (US) examinations
≤5 >5 64.7 (22) 35.2 (12) NA NA
Indications for US more prevalent and US specificity lower in obese womena. Mean number of US examinations among overall population in Sweden was 2.6 in 2017 [3].
Antacids given during delivery 55.9 (19) Low Adequate prophylactic anticoagulation
intrapartum
100 (34) High Recommended if >4 p according to riskscore in Hem-Arg [23] a Prophylactic anticoagulation postpartum
and duration 42 days 55.9 (19) 26.3 (5) Low Low
Anticoagulation is recommended six weeks postpartum if morbid obesea.
Regional anesthesia during CD 78.6 (11) NA Risk for complication at general anesthesia but regional anesthesia is not always possible to applya.
Prophylactic iv antibiotics in CD 100 (14) High Recommended in all CDa.
CD with additional surgeons (>1) 92.9 (13) High With BMI >35 kg/m2 two surgeons are recommendeda.
Subcutaneous suturing during CD 50 (7) Low >2cm. subcutaneous tissue, suturing is recommendeda.
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5. Discussion
This study found a statistically significant association between obesity and several adverse obstetrical outcomes including increased risk of induction of labor, CD, emergency CD, longer duration of CD, higher total blood loss and increased mean fetal birthweight. Our audit of adherence to new guidelines for morbidly obese women showed varying compliance.
In the Orebro region, 100% of the deliveries were reported to the national register, SPR [24]. Validity is continuously evaluated, however this evaluation investigated only a limited number of parameters [25]. SPR is a new register, developed in 2013, which enable us to compare outcomes between hospitals and regions [26]. In studies using epidemiological data confounding factors can be problematic, and results should therefore not be considered as definitive evidence for clinical intervention. Epidemiological data can however generate new hypotheses for further investigation [27].
Age did not differ between the two groups, in contrast to prior studies [28], in addition to our expectations. We presumed that a higher rate of previous CD and lower rate of null parity in the obese group would result in an increased age in that group. Socioeconomic status differed significantly between the groups. Poor socioeconomic situation is strongly associated to obesity [29] and BMI is often used as a surrogate variable for socioeconomic level when lacking other data. Due to this co-dependence, no adjustment to differences in socioeconomic status was made in our analysis.
Our results, which indicate increased risk of CD among obese women, are in accordance with previous international and Swedish studies [2,13,15,28,30–32]. Previous studies also support our observation with increased prevalence of emergency CD [2,30,31,33]. One explanation to the elevated rates of CD could be the mechanical effect of extra pelvic adipose tissue that may affect the descent of the fetus head [32,34]. Other possible reasons could also be obese
women’s impaired response to oxytocin [32], decreased myometrical contractility [15] and pregnancy complications such as preeclampsia or gestational diabetes [13]. Furthermore, obese women’s tendency to have larger babies, in consistence with our study, might increase CD rates [2,28,35]. Our results report an increased frequency of induction in obese women, which is consistent with previous papers [13,30,31,36]. Decreased rate of cervical dilation [34], higher induction rates and subsequent increased amounts of failed inductions in obese women could also be a reason for the increased CD rates [37]. Analysis of differences in indications for CD or induction in relation to BMI were not within the scope of this study.
16 The lower prevalence of instrumental VD among obese women in this study is in contrast to previous studies [13,28,31,36], but is consistent with our expectations. We presumed the prevalence of instrumental VD to be decreased among the obese women because of their lower prevalence of null parity. Additionally, the obese women had a higher prevalence of previous CD, something that increases the likelihood of future CD and thus decreasing the likelihood of VD. The speculated reason for the lower instrumental VD rate, in this study, could also be because of the clinician’s decision to perform a CD instead of a complicated instrumental VD [38].
A possible association with hemorrhage and obesity has been reported with variable results. Most of previous studies show increased hemorrhage when obese [13,20,28,30,32], both in VD and CD [13,32] but in one study, with a study population of 369.347 women, hemorrhage (>500ml) was unaffected by maternal BMI [33]. The atonic uterine, due to LGA baby or prolonged delivery, could be one explanation for more bleeding in obese women [31,39]. Well-known issues regarding hemorrhage are difficulties in accurately estimating total blood loss in addition to varying definitions of postpartum hemorrhage. Previous studies had either no definition or a different definition of hemorrhage compared to our study. In Sweden small amounts of blood loss is measured by clinical judgement, while greater blood loss is measured by weighing (for example pads), which means that measurements of greater blood loss tends to be more precise. This could cause bias towards null because it is independent of BMI [33]. The lower blood loss in the obese group during CD were surprisingly, when compared to previous studies showing that the odds of hemorrhage after CD are even greater than after VD [13,32]. The reason for this is unclear but one possible explanation is potential outliers
affecting the results.
The varying compliance to the new guidelines might reflect different approaches among clinicians combined with inadequate information regarding new guidelines. Only 34 patients were included in this study, which limits the possibility to generate conclusive results. Future evaluation is required since the guidelines are recently introduced. Moreover, further work in order to improve the compliance is needed, since morbidly obese women are a high-risk group for many adverse maternal outcomes. To provide a better overview of the compliance it is necessary to compare compliance before and after implementation of the new guidelines. One strength of our study is our high study population amount. Another strength is that maternal weight is not reported. The true weight tends to be underestimated if self-reported, which may be true to an even greater extent with increasing weights [40]. Weight
17 represent an important parameter in our study and incorrectly reported weights might skew the results. There is also decreased likelihood of misclassification of the women´s BMI, since gestational length at admission to antenatal care did not differ among the groups. If
gestational length had differed between the two groups, it could have led to misclassification of BMI due to the possibility that some of the women might have gained additional weight prior to registration. Another strength is that our data was prospectively recorded into SPR, although we collected data retrospectively. Furthermore, no previous study regarding delivery outcomes in obese women in the Örebro region exists and there are only few studies based on the SPR. No selection bias should be present since we included all simplex deliveries.
Our study analyzed data retrospectively, which means association between obesity and outcomes can be analyzed but causative factors cannot be established. Another limitation is the high number of excluded individuals, which might lead to bias. Many excluded women had missed data regarding level of education, thus may impact socioeconomic status. There were higher rates of excluded obese women and the effect of this is uncertain. We did not investigate the prevalence of previous VD, which might affect mode of delivery and should be investigated further.
Further research is needed to understand the causal mechanism between maternal obesity and adverse obstetrical outcomes. Future studies are also needed to understand the association of increased CD rates and obesity. For example, the indication of our outcomes and the influence of other contributory factors such as, gestational diabetes, preeclampsia and socioeconomic status, would be of interest to analyze. Additionally, there are several parameters in SPR of interest to investigate in the future, but many of them were found incompletely recorded. It is unclear exactly why adverse outcomes occur and how to clinically manage maternal obesity in best possible way. Additional research in the area may improve the management of obese pregnant women.
Maternal obesity when pregnant has disadvantages for both the mother and fetus and may be one of the most important risk factors for maternal and perinatal morbidity. Health care providers need to prevent unequal care impacting obstetrical outcomes in obese patients. Also, it is important to address weight management and pre-pregnancy maternal care to prevent increase in obesity. Obese women should be encouraged to and provided support in losing weight prior to pregnancy and to control weight when pregnant. To prevent maternal obesity, a program of public health interventions is needed.
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6. Conclusion
Obesity, when pregnant, is highly prevalent in the Örebro region and maternal pre-pregnancy obesity is a significant risk factor for adverse maternal delivery outcomes. Maternal obesity is associated with significantly increased risk of induction of labor, CD, longer CD duration, repeated CD, higher total blood loss and higher fetal birthweight.
Compliance among health care providers, to new regional guidelines regarding maternal care for obese women, is overall high but continuous follow-up is warranted.
The rate of maternal obesity is increasing, and it is an important, and probably, preventable risk factor for maternal morbidity, which clinicians must bear in mind when caring for obese pregnant women.
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25. Petersson K, Persson M, Lindkvist M, Hammarström M, Nilses C, Haglund I, m.fl. Internal validity of the Swedish Maternal Health Care Register. BMC Health Services Research [Internet] 2014 [citerad 2018 okt 10];14. Available from:
http://bmchealthservres.biomedcentral.com/articles/10.1186/1472-6963-14-364
26. Stephansson O, Petersson K, Björk C, Conner P, Wikström A-K. The Swedish Pregnancy Register - for quality of care improvement and research. Acta Obstetricia et Gynecologica Scandinavica 2018;97:466–76.
20 27. Taube A. endast ett steg i en vetenskaplig process. 2008;4.
28. Onubi OJ, Marais D, Aucott L, Okonofua F, Poobalan AS. Maternal obesity in Africa: a systematic review and meta-analysis. J Public Health (Oxf) 2016;38:e218–31.
29. Newton S, Braithwaite D, Akinyemiju TF. Socio-economic status over the life course and obesity: Systematic review and meta-analysis. PLoS One [Internet] 2017 [citerad 2018 okt 24];12. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5433719/
30. Heslehurst N, Simpson H, Ells LJ, Rankin J, Wilkinson J, Lang R, m.fl. The impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysis. Obesity Reviews 2008;9:635–83.
31. Ramö Isgren A, Kjølhede P, Blomberg M. Obstetric Outcomes in Adolescents Related to Body Mass Index and Compared with Low-Risk Adult Women. J Womens Health (Larchmt)
2017;26:426–34.
32. Chu SY, Kim SY, Schmid CH, Dietz PM, Callaghan WM, Lau J, m.fl. Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes Rev 2007;8:385–94.
33. Ovesen P, Rasmussen S, Kesmodel U. Effect of prepregnancy maternal overweight and obesity on pregnancy outcome. Obstet Gynecol 2011;118:305–12.
34. Harvey MW, Braun B, Ertel KA, Pekow PS, Markenson G, Chasan-Taber L. Prepregnancy Body Mass Index, Gestational Weight Gain, and Odds of Cesarean Delivery in Hispanic Women. Obesity (Silver Spring) 2018;26:185–92.
35. Morken N-H, Klungsøyr K, Magnus P, Skjærven R. Pre-pregnant body mass index, gestational weight gain and the risk of operative delivery. Acta Obstetricia et Gynecologica Scandinavica 2013;92:809–15.
36. Lutsiv O, Mah J, Beyene J, McDonald SD. The effects of morbid obesity on maternal and neonatal health outcomes: a systematic review and meta-analyses. Obes Rev 2015;16:531–46. 37. Schuster M, Madueke-Laveaux OS, Mackeen AD, Feng W, Paglia MJ. The effect of the MFM
obesity protocol on cesarean delivery rates. Am. J. Obstet. Gynecol. 2016;215:492.e1-6. 38. Ramos SZ, Waring ME, Leung K, Amir NS, Bannon AL, Moore Simas TA. Attempted and
Successful Vacuum-Assisted Vaginal Delivery by Prepregnancy Body Mass Index. Obstet Gynecol 2017;129:311–20.
39. Blomberg M. Maternal obesity and risk of postpartum hemorrhage. Obstet Gynecol 2011;118:561–8.
40. Baeten JM, Bukusi EA, Lambe M. Pregnancy complications and outcomes among overweight and obese nulliparous women. Am J Public Health 2001;91:436–40.
21
Fetmas påverkan på förlossningsutfall
Fetma har ökat både i världen och i Sverige under de senaste årtionden. Under 2017 var det 15 % i Sverige och 18 % i Örebro som var feta under graviditet. Fetma innebär att man har body mass index (BMI) som är lika med eller överskrider 30 kg/m2. Tidigare studier visar att fetma under graviditeten medför många risker både för barnet och mamman, så som ökad frekvens av ven propp, missfall, dödfött barn, graviditetsdiabetes, havandeskapsförgiftning och till och med dödsfall av modern. Studier visar också att frekvensen kejsarsnitt ökar i allmänhet och att feta kvinnor löper ökad risk att bli förlöst med kejsarsnitt.
Denna studie analyserade förlossningsutfall hos feta jämfört med icke-feta kvinnor, förlösta på Örebro universitetets sjukhus, från första januari 2015 till och med sista juni 2018. Av de 6846 inkluderade kvinnorna visas det tydliga skillnader i förlossningsutfall mellan att vara fet och att inte vara det. Det är observerade skillnader, med bland annat ökat frekvens hos feta kvinnor gällande igångsättningsfrekvens, kejsarsnitt, duration av kejsarsnitt, ökad vikt på barnet, ökad total blödningsmängd, minskad frekvens vaginal förlossning och även sämre självrapporterad hälsa före, under och efter graviditet.
Våra resultat stämmer väl överens med tidigare studier som också visar markanta skillnader i förlossningsutfall i förhållande till BMI. Dessa ogynnsamma utfall hos feta kvinnor, som också medför extra kostnader och resurser, måste tas i beaktande för att säkra kvaliteten på handläggning och ge en jämlik vård av gravida kvinnor.
22
Cover letter
1st November, 2018
Author: Linnéa Sundman, Örebro University, Sweden
Co-author: Ann-Kristin Rönnberg, Department of Obstetrics and Gynecology, Örebro University Hospital, Sweden
Correspond to: Linnea.rosen.91@ hotmail.com
Dear editors of Journal of Obstetrics and Gynecology
Would you please consider this manuscript “The impact of obesity on outcome of delivery-a retrospective observational study in a Swedish obstetric population” for publication in Journal of Obstetrics and Gynecology.
We investigated several obstetrical outcomes in obese compared to non-obese women who delivered in Örebro University hospital. Our data are collected from a new Swedish
Pregnancy register. Our study report several adverse maternal obstetrical outcomes in obese women including increased rate induction of labor, cesarean delivery, longer cesarean duration, higher total blood loss, heavier infants and decreased rates of vaginal deliveries. Furthermore, obese women report poorer self-reported health both before, during and after delivery.
Rates of obesity are increasing to an epidemic proportion and our results report important adverse delivery outcomes in obese women in Örebro region, which most likely generate increased hospital admission costs and extra needed resources. Moreover there are few studies made from the Swedish Pregnancy register. With this in mind, publication of this manuscript would be appropriate.
Our manuscript has not been published earlier and is not under consideration for publication elsewhere.
Thank you for consideration. Sincerely,
23
Utökad etisk reflektion
Vår studie består av registerstudie och journalgranskning. All data är presenterad
avidentifierat och på gruppnivå. Inhämtande av data har godkänts av verksamhetschef på kvinnokliniken Region Örebro inom ramen för kvalitetsarbeten.
Medgivande från patienterna att vara med i registret finns men inget har inhämtats för att genomföra denna studie, vilket är en nackdel då det kan upplevas som intrång och kräkning av integriteten, autonomin och sekretessen att delta utan godkännande. Om samtyckte skulle inhämtas kan kvinnan känna sig utpekad och om hon upplevt en traumatisk förlossning kan dåliga minnen väckas till liv igen. Studien har inte utsatt patienterna för någon medicinsk skada eftersom studien är retrospektiv och därmed inte har påverkat varken behandling eller handläggning. Vår studies nytta är att eventuella negativa utfall hos obesa kvinnor upptäcks och därmed eventuellt ändrar handläggning, så att komplikationer och risker förebyggas, till en mer jämlik vård.
Vid journalgranskningen var syftet att utvärdera omhändertagandet med tanke på kraftig obesitas, vilket kan vara ett känsligt ämne och upplevas som utpekande. En risk finns också att man finner att de med fetma har blivit orättvist behandlade, vissa bättre andra sämre, och därmed kännas kränkta. Att det endast var 34 patienter med kraftig fetma leder även till en risk för skada genom att det finns en teoretisk möjlighet att kunna identifiera någon i gruppen. Nyttan med journalgranskningen är att man kan upptäcka dålig följsamhet till
vårdprogrammet gällande kraftigt obesa kvinnor och därmed leda till att man kan ändra rutiner, säkra kvalitén på omhändertagandet och ge en jämlik vård.
24
Appendix 1
Bakgrund
Obesitas är vanligt förekommande hos gravida kvinnor och kopplat till en ökad risk för ett flertal graviditets- och förlossningskomplikationer. Cirka 16 % av gravida kvinnor i Örebro län har en obesitas (BMI>30) och 5 % av dem har en allvarlig grad, med BMI >35. Komplikationer som ses är t.ex. en ökad förekomst av missfall, blodtryckssjukdomar inklusive preeklampsi, graviditetsdiabetes, trombossjukdom, utdragen förlossning och riklig postpartum blödning.
Risken för sectio ökar med högre BMI och barn till kvinnor med obesitas har en ökad risk för medfödd missbildning, prematur födelse och att födas små- (SGA) eller stora-för-tiden (LGA). Ökad risk för intrauterin fosterdöd samt ökad perinatal mortalitet och morbiditet finns även beskrivet i studier.
Grad av obesitas enligt WHO.
MHV
• Pre-gravid rådgivning vid obesitas bör erbjudas alla kvinnor med obesitas (BMI>30) som överväger graviditet. Målsättning är att stödja och uppmuntra kvinnan till att
minska/normalisera BMI innan en eventuell graviditet. Stöd i form av
nutritionist/dietistkontakt/KBT/remiss för överviktsoperation och/eller fysisk aktivitet på recept (FaR) bör erbjudas.
• Eventuell förekomst av ätstörning bör penetreras i anamnes och relevant vårdkontakt för behandling erbjudas.
• Överväg screening för typ 2 diabetes redan innan graviditet.
• Kvinnor med obesitas bör få råd om intag av Folsyra 5mg x 1 med start cirka en månad innan graviditet och fram till slutet av första trimester.
Inskrivning av gravid kvinna med obesitas
Vikt och längd mäts vid första inskrivningsbesök. Viktkontroll i samband med alla besök uppmuntras. Viktökning inom intervallet 5-9kg rekommenderas under graviditet. Patientinformation med viktgraf delas ut i samband med inskrivningsbesök (bilaga 1).
BMI
Grad 1 30.0–34.9
Grad 2 35.0–39.9
Grad 3 >40
BMI (inskrivning) Rekommenderad viktökning (kg)
Undervikt <18.5 12.5-18.0
Normalvikt 18.5-24.9 11.5-16.0
Övervikt 25.0-29.9 7.0-11.5
Obesitas/Fetma >30 5.0-9.0
25 • Vid BMI >35 vid inskrivning skickas remiss till SMVC. Syftet med tidig remiss är
läkarbedömning av eventuell indikation för tidigt insatt (< 12v) ASA och/eller
trombosprofylax och samtidigt bedöms även behov av utökade kontroller. Vid eventuell ordination av läkemedel kontaktas alltid patienten av läkare på SMVC. Om ingen indikation
för behandling/kontroll finns kommer inte heller patienten att kontaktas. Gravida med extrem
fetma (BMI>40, grad 3) planeras alltid in för ett besök på SMVC för förlossningsplanering v 32-34.
• Vitamin D 10 mikrogram x 1 (5 droppar) rekommenderas under graviditet och amningsperiod till alla med obesitas.
• Vid blodtryckskontroller ska stor manometer-kuff användas om överarms omkrets >33cm. • OGTT (2h 75 g OGTT) v 24-28 rekommenderas för alla gravida med BMI >35.
SMVC
• Gravida med grad 2-3 obesitas (BMI >35) screenas med avseende på indikation för profylax av preeklampsi/IUGR (ASA), trombos (LMWH) och behov av utökade kontroller genom tidig remissbedömning av läkare SMVC. Vid eventuell indikation för ordination av läkemedel kontaktas alltid patienten av läkare på SMVC. Om ingen indikation för behandling finns vid
remissbedömningen behöver inte heller patienten kontaktas.
• Lågdos ASA (T Trombyl 75 mg x 1 mellan v 12-36) till gravida med hög risk för preeklampsi reducerar risk för PE med ca 10-20 % och reducerar även risk för prematurbörd, neonatal död och fetal tillväxthämning med 10 %.
Högriskgraviditet som bör erbjudas ASA är:
• Tidigare graviditet med svår eller tidig PE/IUGR • diabetiker med kärlkomplikation
• Antifosfolipidsyndrom (APS)
• Kronisk njursjukdom/nedsatt njurfunktion
• Autoimmun sjukdom (t.ex. SLE med cardiolipin-ak) • Gravida med >2 kliniska riskfaktorer*
*Kliniska riskfaktorer: BMI>30, ålder >40 eller <20 år, etnicitet (mörkhyad), hereditet, 0-para, flerbörd, tidigare PE, kronisk HT, diabetes, njursjukdom, APS, autoimmun sjukdom, gravid genom äggdonation
• Bedömning av indikation för antepartal trombosprofylax baseras på Hem-ARG rekommendation (>4 riskpoäng).
1 poäng 2 poäng 3 poäng >4 poäng1 Mycket HÖG
26 Heterozygot FV Leiden Heterozygot protrombin-mutation Fetma6 Inflammatorisk tarmsjukdom
Hereditet för VTE (1a grad släkting) Ålder >40 år Hyperhomocysteinemi 3 Sectio7 Ablatio7 Preeklampsi7
Annan större riskfaktor
Protein S-brist4 Protein C-brist Immobiliserin g5 Homzygot FV Leiden Homozygot protrombin -mutation Dubbel-mutationer Tidigare VTE APS utan VTE4 Antitrombinbrist med/utan VTE Upprepad VTE APS med VTE
1) Vid överstimulering (IVF) rekommenderas trombosprofylax tom gravv13. 2) Ska ha högdosprofylax.
3) OBS! referensvärden varierar beroende på laboratorium. Halverade värden ses normalt vid graviditet. 4) OBS! Kvinnor med APS, lupusantikoagulans eller cardiolipin-ak ska även ordineras ASA 75 mg/dag. 5) Vid gipsbehandling och strängt sängläge ges korttidsprofylax.
6) Fetma (BMI ≥30) vid inskrivning MVC. 7) Riskfaktor för trombos post partum.
• Viss ökad risk för fetala missbildningar vid maternell obesitas. RUL utförs av UL-certifierad barnmorska om ingen ytterligare riskfaktor finns. Dock låg tröskel för läkarbedömning vid oklarhet då fetma kan försämra bildkvalitet.
• Kvinnor med Grad 3 Fetma (BMI > 40) planeras för läkarbesök SMVC v 32-34 för information och förlossningsplanering (oftast gemensamt mottagningsbesök med obstetriker + narkosläkare). Förlossningsplanering enligt CHECKLISTA (bilaga 2) dokumenteras i Obstetrix. Aktuell vikt noteras för att säkra rätt kapacitet hos
förlossningssäng/operationsbord. Fetal viktskattning vid detta besök utförs endast vid misstanke om IUGR och/eller icke palpabelt SF-mått.
• Vid eventuell op-anmälan av patient med BMI>40 noteras aktuell vikt i Provisio för adekvat förberedelse/personal/kompetens och ev. lyft finns till hands.
27 Förlossning
• Gravid med BMI>35 bör hänvisas till förlossning på USÖ. • Riskklassificering GUL vid BMI >35 utan annan riskfaktor.
• Vid inskrivning av kvinna med BMI >40 och avsaknad av journalförd förlossningsplan meddelas både förlossningsjour och narkosjour för planering enligt CHECKLISTA
(bilaga 2).
• Intravenös infart (grön) sätts tidigt i förlossningsförlopp vid BMI >40. Överväg ytterligare infarter vid fler riskfaktorer för stor blödning alt. instrumentell förlossning.
• Frikostig användning av ultraljud om osäkerhet över fosterläge vid yttre palpation. • Förlossnings-EDA rekommenderas vid BMI >40 om ingen kontraindikation finns. En väl
fungerande EDA minskar risken för behov av intubation vid eventuellt akut sectio eller annan akut obstetrisk åtgärd.
• Vid BMI >40 bör engångsdos T Omeprazol®/Ranitidin® 20 mg per os erbjudas vid aktiv förlossning. Syftet är att höja magsaftens låga pH och minska skador av en eventuell aspiration.
• Kvinnor med obesitas har en ökad risk för värksvaghet/långsam progress av öppningsskede och Oxytocin i sedvanlig dosering är ibland otillräckligt. På
läkarordination kan högre Oxytocindos (>180ml/h) övervägas för att optimera värkarbetet. Observans på risk för övervätskning på grund av antidiuretisk effekt av oxytocin.
• Aktiv handläggning av placentaskifte rekommenderas alltid vid BMI >40 pga ökad risk för atonisk uterus och stor blödning.
Operation - Sectio hos kvinna med obesitas
• Två operatörer bör eftersträvas vid BMI >35.
• Antibiotika profylax Cefuroxim 1.5g x 1 iv rekommenderas vid alla sectio. Optimal tidpunkt ca 30 minuter innan incision (vid pc-allergi: Klindamycin 600 mg x 1 iv). • Hög prioritet att hinna anlägga regionalanestesi (Spinal/EDA) vid grad 3 obesitas (BMI
>40) med tanke på hög maternell komplikationsrisk vid intubation.
• Fascia sutureras med monofil sutur (PDS) och subkutan fettväv sutureras med minst en rad om vävnadsdjup >2cm (reducerar risk för serom, infektion och sårruptur).
• Postoperativ trombosprofylax minst 7 dagar vid BMI >30. För kvinnor med grad 3 obesitas (BMI >40) rekommenderas förlängd profylax med sex veckors behandling. Dosering utifrån postoperativ vikt enligt Hem-ARG rekommendation.
Postpartum (THG/Medicinskt BB/MHV)
• Oavsett förlossningssätt bör alla kvinnor med obesitas (BMI >30) bedömas avseende indikation för trombosprofylax innan hemgång. OBS! även vid THG från
28 förlossningsavdelningen. Bedömning sker utifrån Hem-ARG rekommendation (>2
riskpoäng) enligt ovan. Första dos LMWH kan ges 4 timmar efter partus, ingen
provtagning behövs vid behandlingsduration <6v. Dosering baseras på vikt postpartum. • Uppmuntra tidig mobilisering och bruk av kompressionsstrumpor 6 v postpartum, oavsett
förlossningssätt.
• Erbjud sjukgymnastkontakt vid bristande mobilisering av inneliggande kvinna med svår obesitas.
• Låg tröskel för läkarbedömning vid symtom/tecken på trombossjukdom.
• Ökad risk för infektion postpartum (endometrit, sår- och urininfektion) hos obesa kvinnor. Låg tröskel för läkarbedömning av operationssår vid misstanke om infektion i samband med omläggning eller tillkomst av feber.
• Kvinnor med obesitas har, av varierande orsaker, en lägre amningsfrekvens och bör erbjudas utökat stöd via amningsmottagningen.
• Vid efterkontroll inom MHV bör motiverande samtal med information om vikten av viktminskning postpartum ges. Summera viktuppgång under graviditeten och informera om möjlighet till remiss till Överviktsenheten USÖ via MVC läkare (behövs
behandlingsansvarig läkare på remiss). Stöd i form av
nutritionist/dietistkontakt/KBT/remiss för GBY och/eller fysisk aktivitet på recept (FaR) bör erbjudas via primärvården.
Referenser
CMACE/RCOG guidelines. Management of Women with Obesity in Pregnancy. UK 2010. Hemostasrubbningar inom obstetrik och gynekologi, SFOG 2012.
Mödrahälsovård, Sexuell och Reproduktiv Hälsa, SFOG 2016. Marchi et al. Obesity reviews 16:2015.
Gestational Weight Gain, reexamining the guidelines. Institute of Medicine 2009. Practice Guidelines for Obstetric Anesthesia. Anesthesiology 2016.
Anesthetic management of obstetric patients: what is the evidence supporting guidelines? Anaesth Intensive Care 2016.
Riktlinje för anestesi vid kejsarsnitt. Nr 21-8. 2013-09-09. SFOAI, SFAI.
Bilaga 1. Patientinformation för gravid med obesitas
Bilaga 2. Förlossningsplan vid grad 3 fetma, checklista
Ann-Kristin Rönnberg Ann-Christine Nilsson
29
Kvinnokliniken Kvinnokliniken
Malin Ugarph-Edfeldt Gill Kullberg
Överläkare Läkarchef
